chain-studio/integration_test/skew_smoke_test.dart

// Version-skew smoke — the DEV Studio against an OLDER, released
// hub binary. The two worst live bugs of the project were skew
// bugs (ABI 1.0/1.1, a 0.21 hub without the ListInvocations RPC
// rendered as "hub not reachable"), and no test ever ran the
// combination operators actually have: a Studio that is newer
// than its hub.
//
// Run through the platform repo's scripts/skew-smoke.sh, which
// resolves the old binary and isolates $HOME:
//
//   CHAIN_BIN=<old released chain> \
//   flutter test integration_test/skew_smoke_test.dart -d macos
//
// Invariants per page (the hub IS running and healthy):
//   * never "nicht erreichbar" — a reachable hub must never be
//     rendered as unreachable, whatever RPCs it is missing
//   * never raw error text (gRPC walls, UnimplementedError, ...)
//     — missing RPCs must surface as classified, localised states
//     ("braucht eine neuere Hub-Version", feature-off, ...)

import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:integration_test/integration_test.dart';
import 'package:shared_preferences/shared_preferences.dart';

import 'package:chain_client_sdk/chain_client_sdk.dart' show HubEndpoint;
import 'package:chain_studio/data/hub.dart';
import 'package:chain_studio/main.dart';

import '../test/integration/hub_fixture.dart';

const _destinations = <String>[
  'welcome',
  'store',
  'doctor',
  'flows',
  'audit',
  'approvals',
  'runs',
  'federation',
];

const _rawErrorMarkers = <String>[
  'gRPC Error',
  'UnimplementedError',
  'SocketException',
  'Instance of',
  'StackTrace',
];

Future<void> _pumpFrames(WidgetTester tester, [int frames = 20]) async {
  for (var i = 0; i < frames; i++) {
    await tester.pump(const Duration(milliseconds: 100));
  }
}

String _renderedText(WidgetTester tester) {
  final buf = StringBuffer();
  for (final w in tester.widgetList<Text>(find.byType(Text))) {
    buf.writeln(w.data ?? w.textSpan?.toPlainText() ?? '');
  }
  for (final w in tester.widgetList<SelectableText>(
    find.byType(SelectableText),
  )) {
    buf.writeln(w.data ?? '');
  }
  return buf.toString();
}

void main() {
  IntegrationTestWidgetsFlutterBinding.ensureInitialized();

  testWidgets('dev Studio against the released hub: reachable is never '
      'rendered unreachable, no raw errors', (tester) async {
    final fixture = await HubFixture.start(skipIfBinaryMissing: false);
    addTearDown(fixture!.dispose);

    final binary = (await HubFixture.binaryPath())!;
    final version = await Process.run(binary, ['--version']);
    // Surfaced in the runner output so the log states which skew
    // pair was actually exercised.
    // ignore: avoid_print
    print('skew-smoke: hub binary = ${(version.stdout as String).trim()}');

    SharedPreferences.setMockInitialValues({});
    await tester.pumpWidget(
      const StudioApp(
        initialThemeMode: ThemeModeValue.dark,
        initialLocale: Locale('de'),
      ),
    );
    await HubService.instance.reconnect(
      HubEndpoint(host: '127.0.0.1', port: fixture.port),
      authToken: null,
      persist: false,
    );
    await _pumpFrames(tester, 30);

    final shell = tester.state<StudioShellState>(find.byType(StudioShell));
    final violations = <String>[];
    for (final id in _destinations) {
      shell.navigateTo(id);
      await _pumpFrames(tester, 25);
      // Let in-flight gRPC frames land in REAL async before the next
      // navigation disposes the page: grpc-dart 4.2 adds incoming
      // data to an already-closed controller when a cancel races the
      // response (call.dart:395, unguarded `_responses.add`) — an
      // upstream bug that would fail the walk spuriously.
      await tester.runAsync(
        () => Future<void>.delayed(const Duration(milliseconds: 150)),
      );
      final text = _renderedText(tester);
      if (text.contains('nicht erreichbar')) {
        violations.add(
          'page "$id" claims the hub is unreachable although the '
          'fixture hub is healthy',
        );
      }
      for (final marker in _rawErrorMarkers) {
        if (text.contains(marker)) {
          violations.add('page "$id" renders raw error text "$marker"');
        }
      }
    }
    // Tear the app down BEFORE the fixture teardown closes the hub:
    // page subscriptions cancel while the channel is still alive, so
    // the shutdown cannot race live streams into add-after-close.
    await tester.pumpWidget(const SizedBox.shrink());
    await tester.runAsync(
      () => Future<void>.delayed(const Duration(milliseconds: 200)),
    );
    await tester.pump(const Duration(minutes: 6));
    expect(violations, isEmpty, reason: violations.join('\n'));
  });
}